The relative contributions of carotid duplex scanning, magnetic resonance angiography, and cerebral arteriography to clinical decisionmaking: a prospective study in patients with carotid occlusive disease.

PURPOSE: Recent reports suggest that 80% to 90% of patients can safely undergo carotid endarterectomy on the basis of duplex scanning alone without cerebral angiography. Other investigators have recommended that a complementary imaging study such as magnetic resonance angiography (MRA) also be obtained. METHODS: We prospectively evaluated 103 consecutive patients with carotid occlusive disease. Eighty percent of patients were symptomatic. All 103 patients underwent duplex scanning and arteriography. Additional noninvasive tests included computed tomography, magnetic resonance imaging, and MRA in 50%, 56%, and 48% of patients, respectively. At a multispecialty conference all studies except angiograms were reviewed, and a treatment decision was made by a panel of attending vascular surgeons, neurosurgeons, and neurologists. The cerebral angiograms then were reviewed and changes made to final treatment plans were noted. RESULTS: After review of noninvasive studies, 30 of 103 of patients (29%) were believed to require arteriography because of diagnostic uncertainty of carotid occlusion in three patients, suggestion of nonatherosclerotic disease in four, suggestion of proximal disease in two, suboptimal noninvasive studies in one, and uncertainty of therapy despite good-quality noninvasive studies in 20 patients primarily with borderline stenoses and unclear symptoms. In 10 of these 30 patients (33%) management decisions were changed on the basis of angiogram results. Of the remaining 73 patients (71%) in whom the panel felt comfortable proceeding with operative or medical therapy without angiography, only one patient (1.4%) would have had management altered by results of angiography. MRA results concurred with duplex findings in 92% of studies, but did not alter management in any patient. CONCLUSIONS: In patients with good-quality duplex images, focal atherosclerotic bifurcation disease, and clear clinical presentation, treatment decisions can be made without arteriography. In 30% of patients angiography is useful in clarifying decisionmaking. MRA is unlikely to influence management decisions and is thus rarely indicated.

Comparative analysis of percutaneous transluminal angioplasty and operation for renal revascularization.

Contemporary patients requiring renal revascularization often have diffuse atherosclerosis, and increasingly undergo intervention for salvage of renal function rather than control of hypertension alone. Risk-benefit analyses and outcome data are difficult to obtain, since few reports have analyzed a modern, unselected series of consecutive patients subjected to renal revascularization by surgical as well as interventional techniques. We reviewed our 5-year experience with 76 consecutive renal revascularizations in 63 patients. Indications for intervention were hypertension and renal salvage, 60 percent (n = 38); hypertension, 24 percent (n = 15); renal salvage, 9.5 percent (n = 6); and other, 6.5 percent (n = 4). Ninety-four percent (n = 59) of patients had atherosclerotic occlusive disease of the renal arteries. Percutaneous transluminal angioplasty (PTA) was initially performed on 18 renal arteries in 16 patients, of whom 56 percent (n = 9) subsequently required surgical reconstruction. Fifty-eight surgical reconstructions were performed in 56 patients and consisted of aortorenal bypass (n = 27), aortorenal endarterectomy (n = 18), and extra-anatomic bypass (n = 13). Concomitant aortic replacement was required in 57 percent (n = 32) of patients. Preoperative risk factors and operative indications did not differ between the PTA and surgical reconstruction groups. Morbidity and mortality rates associated with PTA were 33 percent and 4.8 percent, respectively, while for surgical treatment the morbidity rate was 7 percent and the mortality rate 5.3 percent (P = NS). Functional improvement was achieved in 74 percent of surgically treated patients compared with 22 percent of PTA-treated patients (P < 0.01). Actuarial renal artery primary patency at 48 months was 81 percent for the surgery group and 17 percent for the PTA group (P < 0.01). Aortorenal bypass, endarterectomy, and extra-anatomic bypass were equally efficacious (P > 0.05). The results of surgical reconstruction are excellent, offering more durable patency and functional improvement than PTA, without increased risk. The operation should be tailored to fit the individual patient's disease, since the results of endarterectomy and bypass procedures are equivalent.

Prospective evaluation of peripheral vascular disease in heart transplant recipients.

PURPOSE: Retrospective reviews suggest that the progression of peripheral vascular disease (PVD) may be accelerated in heart transplant recipients. This study was undertaken to determine the incidence and to identify those risk factors that may be associated with the development or progression of PVD in these patients. METHODS: Between January 1990 and December 1993 a prospective vascular screening protocol including abdominal ultrasonography, Doppler-derived ankel-brachial pressure indexes (ABI), and carotid artery duplex imaging was added to the routine preoperative and annual postoperative evaluation of 239 heart transplant recipients. RESULTS: Thirty-one significant vascular lesions were detected in 10% (24 of 239) of patients 52 +/- 9 years of age at a mean of 3.2 years after transplant. The distribution of lesions included carotid artery stenosis (11), femoropopliteal occlusive disease (10), aortoiliac occlusive disease (five), aortic aneurysm (four), and renal artery stenosis in one patient. Revascularization procedures were performed in 12 (50%) patients (carotid endarterectomy (four), aortobifemoral bypass grafting (three), abdominal aortic aneurysm repair (two), transluminal angioplasty (two), splenorenal bypass (one), and femorotibial bypass grafting (one)). One patient with diabetes mellitus (DM) was found to have noncompressible vessels during pretransplant evaluation. An additional 26 patients (11%), seven with DM, had noncompressible vessels in the lower extremities during the follow-up period. Logistic regression analysis revealed that the development of posttransplant PVD was associated with smoking (p < 0.05) and ischemic cardiomyopathy as an indication for transplantation (p < 0.05). The development of noncompressible vessels was associated with younger age (p < 0.05) and the presence of diabetes (p < 0.05). CONCLUSION: Posttransplant peripheral vascular disease occurred in 10% of heart transplant recipients and is associated with pretransplant ischemic cardiomyopathy and smoking. A previously unrecognized subgroup of patients who have noncompressible vessels after operation is described. If the long-term survival of the heart transplant recipient is to be improved, routine follow-up to identify and treat those patients at greater risk appears justified.

Clinical and CT evaluation of a new stretch polytetrafluoroethylene aortic graft.

A new stretch polytetrafluoroethylene (PTFE) aortic graft became available for clinical use in early 1991. We prospectively evaluated our first 107 stretch aortic PTFE grafts by means of serial CT imaging and compared them with a cohort of concurrently placed Dacron grafts. Stretch PTFE requires no preclotting and is claimed to resist long-term dilation and conform well to anastomoses. Consecutive patients undergoing placement of stretch PTFE grafts were seen at least yearly. Within the first 2 years after implantation, contrast-enhanced CT scans of the abdomen and pelvis were obtained. Caliper measurements were made of the native arteries and the body and any limbs of the aortic grafts. Graft elongation was assessed by noting distortions from the normally circular or minimally ovoid configuration of the grafts on transverse CT images. Indications for grafting were elective repair of abdominal aortic aneurysm in 60 patients, aortoiliac occlusive disease in 31, both aneurysm and occlusive disease in eight, and ruptured abdominal aortic aneurysm in eight. The overall operative mortality rate was 6.5%. There were two early postoperative graft limb thromboses resulting from hypercoagulable states, and there was one graft infection. Mean follow-up was 14.1 months (range 1 to 34 months). CT scans were obtained from 61 patients with stretch PTFE grafts and 10 with concomitantly placed Dacron grafts. Ten patients had two or more postoperative CT scans. Primary stretch PTFE patency was 98% and secondary patency, 100%. There was significantly less dilation of both the graft body and limbs in the stretch PTFE group (body mean 16.5%, range 6.3% to 28.1%; limb mean 19.3%, range 10% to 43%) compared to the Dacron group (body mean 33%, range 22% to 78%; limb mean 62%, range 12.5% to 88.9%) (p < 0.01, unpaired t test).(ABSTRACT TRUNCATED AT 250 WORDS)

Dissection of the external iliac artery in highly trained athletes.

We report a series of four acute external iliac artery dissections occurring in three patients within days of completion of ultraendurance athletic events. Acute dissection of the external iliac artery in highly trained athletes after competition has not been previously documented. A retrospective review of three cases was performed with subsequent follow-up, including imaging and hemodynamic measurements. Dissection was suspected on the basis of duplex imaging results in one case, and arteriography confirmed dissection in all cases. All patients were endurance athletes over the age of 40 years. One patient was found to have bilateral lesions. Treatment in two cases was initiated with percutaneous transluminal angioplasty, one with a successful result and subsequent Plamaz stent placement. In the other case percutaneous transluminal angioplasty was unsuccessful, and operative repair was required with the placement of a graft. The final patient who had bilateral involvement was treated conservatively. At a mean follow-up of 32 months, there have been no complications, and all patients have normal resting hemodynamics. Follow-up duplex imaging shows healing of the dissections in the untreated patient. Histopathologic study in the patient treated with operation disclosed dissection in an otherwise normal arterial wall. Highly trained athletes over the age of 40 are susceptible to external iliac artery dissection, and successful treatment has been achieved by surgical, endovascular, and conservative therapies.

Ruptured ulnar artery pseudoaneurysm.

Ulnar artery aneurysms and pseudoaneurysms are rare lesions that usually occur distal to the wrist and cause symptoms as a result of embolization and not rupture. An elderly woman presented with acute rupture of an ulnar artery pseudoaneurysm proximal to the wrist, which caused severe neurologic compromise as a result of bleeding into Guyon's canal and the carpal tunnel. The patient had a remote wrist fracture resulting in a deformity that allowed the ulnar head to be in proximity to the ulnar artery. Rupture of the volar capsule with chronic abrasion of the artery eventually led to pseudoaneurysm formation and subsequent rupture. Emergency operative treatment with excision of the pseudoaneurysm, ulnar artery ligation, and repair of the volar capsule resulted in complete neurologic recovery without vascular compromise. This case is unique because of the proximal location of the pseudoaneurysm and the presentation with rupture. The anatomy, pathogenesis, and treatment options are discussed. Excision of the pseudoaneurysm with repair of the torn volar capsule is recommended to avoid recurrent problems. Vascular reconstruction is needed in cases where radial arterial flow is inadequate.

Application of computed tomography for surveillance of aortic grafts.

BACKGROUND: This study was undertaken to assess the application of computed tomography (CT) for surveillance of aortic grafts. METHODS: Demographics, operative technique, and graft type and size at the time of implantation of aortic grafts in 178 patients were recorded. CT measurements of graft diameters were made with calipers. Data were analyzed by analysis of variance, multiple regression, and chi-squared methods. RESULTS: One hundred twenty-eight (72%) bifurcated grafts and 50 (28%) tube grafts were placed for aneurysmal disease (49%), aortoiliac occlusive disease (47%), ruptured aneurysm (2.3%), anastomotic aneurysm (1%), and graft aneurysm (0.6%). Mean implant time was 43.3 +/- 3.2 months. A total of 143 Dacron prostheses (74 woven, 69 knitted) and 35 polytetrafluoroethylene prostheses were placed. Mean percentage dilation was 49.2 +/- 4.0 for knitted prostheses, 28.5 +/- 3.0 for woven prostheses, and 20.6 +/- 1.9 for polytetrafluoroethylene prostheses compared with the graft implant size. A significant correlation was seen between graft dilation (more than 50%) and graft construction with knitted prostheses (p < 0.01, Tukey's range test). Complications detected by CT occurred in 24 (13.5%) patients including supragraft aneurysms (seven), distal anastomotic aneurysms (five), proximal anastomotic aneurysms (three), graft infections (two), perigraft fluid collections (two), graft aneurysm with thrombus and distal embolization (two), and nonvascular complications (three). CONCLUSIONS: CT is a useful modality for postoperative imaging of aortic prostheses. Routine surveillance may detect complications before they become clinically apparent.

Aortofemoral graft occlusion: strategy and timing of reoperation.

The authors' experience with 46 patients treated over 8.5 years was reviewed to determine the optimal secondary revascularization procedure after occlusion of a unilateral aortobifemoral graft limb. A total of 64 procedures was performed on these patients to restore and maintain graft patency. Repetitive operations for reocclusion were needed in 14 patients (30%). Transcatheter thrombolytic therapy was used in 14 patients, four as sole therapy and 10 in conjunction with operation. The mean time from aortofemoral grafting to presentation with graft limb occlusion was 59.4 months. Rest pain or severe ischemia was present in 85%, and severe claudication in the remainder. Some 78% had urgent operation after diagnostic angiography and catheter-directed thrombolytic therapy was attempted in 22%. The etiology of graft thrombosis was outflow obstruction in 78.2% of cases. Inflow was obtained by surgical thrombectomy in 35 and by lytic therapy in 13. Extra-anatomic inflow was used in 11 and intra-abdominal thrombectomy or redo aortofemoral grafting in five. Outflow procedures, mainly profundaplasty, were performed in all but five cases (four urokinase and one surgical). Infrainguinal bypass was needed in 10 cases in addition to the groin reconstruction. Catheter-directed thrombolysis was successful in 13 of 14 instances; however, in nine of these residual stenosis was disclosed in the outflow requiring surgical repair. Ultimately, 12 of 14 cases treated with thrombolysis required surgical intervention. Cumulative patency for all procedures was 68%. Complications were seen in 14% of cases. Operative mortality was 5%, and limb salvage was obtained in 85%.(ABSTRACT TRUNCATED AT 250 WORDS)

Distinguishing carotid artery pseudo-occlusion with color-flow Doppler.

BACKGROUND AND PURPOSE: This study was undertaken to determine the impact of color-flow Doppler on the accuracy of noninvasive carotid imaging for distinguishing an internal carotid artery pseudo-occlusion (string sign) from a complete occlusion. METHODS: From January 1985 to January 1994, review of noninvasive vascular studies, arteriograms, and operative reports of 26 consecutive patients undergoing 27 carotid endarterectomies for carotid pseudo-occlusion was performed. Further review was conducted of all patients identified with carotid occlusion by noninvasive testing who underwent confirmatory arteriography during the same interval. RESULTS: Conventional gray-scale duplex scanning (January 1985 to December 1989) correctly identified 3 of 11 (27%) pseudo-occluded internal carotid arteries compared with 15 of 16 (94%) internal carotid artery pseudo-occlusions correctly identified by color-flow Doppler (January 1990 to June 1994) (P < .01). Similarly, carotid occlusion was more accurately identified by color-flow Doppler (33 of 33, 100%) compared with gray-scale duplex scanning (19 of 27, 90%) (P < .01). CONCLUSIONS: The addition of color-flow Doppler to the duplex evaluation of the extracranial carotid circulation improves the accuracy of distinguishing carotid pseudo-occlusion from the occluded internal carotid artery and may obviate the need for arteriography to identify patients with this critical level of carotid stenosis.

Popliteal vascular compression in a normal population.

PURPOSE: Positional popliteal artery obstruction is believed to be an important factor contributing to popliteal artery entrapment syndromes. This study was undertaken to define the positional anatomy and physiologic condition of the vessels in the popliteal fossa in groups of highly trained and normally active young men and women. We postulate that at least some symptom-free individuals can occlude the popliteal artery with leg positioning. METHODS: Seventy-two limbs were evaluated in 36 subjects. Symptom-free subjects were recruited in four groups: normally active men, normally active women, male competitive runners, and female competitive runners. All subjects underwent noninvasive testing that included resting segmental limb pressures and Doppler waveforms and color-flow duplex imaging with the leg in the neutral position and then with knee extension with active and passive dorsiflexion and plantar flexion of the foot. Subjects unable to occlude the popliteal artery with positioning were then exercised, and studies were repeated. Magnetic resonance imaging, with magnetic resonance angiography, was conducted on 14 subjects, with each leg studied in the neutral position and with active positioning. RESULTS: Positional popliteal arterial occlusion occurred in 38 of 72 limbs (53%). No intergroup comparisons were statistically significant. The response of each leg was symmetric in 89% of subjects. No subject who could not occlude the popliteal artery at rest was able to do so with exercise. Magnetic resonance imaging disclosed normal anatomy in all subjects and showed the location of popliteal occlusion to be at the level of the soleal sling, with positional compression by the soleus muscle, the lateral head of the gastrocnemius, the plantaris, and popliteus muscles. CONCLUSION: Popliteal arterial occlusion can be induced in 53% of subjects with simple leg positioning caused by myofascial compression. This must be considered when evaluating patients for intervention on the basis of physiologic testing of the popliteal vessels.

Critical carotid artery stenosis: diagnosis, timing of surgery, and outcome.

PURPOSE: Patients with critical carotid artery stenoses have been considered to be at high risk for carotid artery occlusion necessitating urgent or emergency endarterectomy once the stenosis is identified. Included in this group of patients are those with carotid string sign or atheromatous pseudoocclusion (APO). This review was conducted to determine the impact of the severity of stenosis including APO on the treatment and outcome of patients undergoing carotid endarterectomy. METHODS: The records of 203 consecutive carotid endarterectomies performed in 197 patients were reviewed in detail. Patients were stratified into a critical stenosis group (80% to 99% diameter) and noncritical stenosis group based on noninvasive vascular laboratory and carotid arteriography results. Comparisons were performed of demographic data, atherosclerotic risk factors, carotid artery disease presentation, interval between arteriography and endarterectomy, operative details, and surgical results between the critical and noncritical groups and between patients in the critical group with and without APO. RESULTS: Carotid endarterectomies were performed on 91 critical carotid artery stenoses and 112 noncritical stenoses. The groups did not differ significantly with regards to demographics, risk factors, carotid artery disease presentation, mean back pressure, and operative use of shunt or patch closure. For the critical group the interval between arteriography and endarterectomy was 8.63 +/- 2.38 days compared with 9.64 +/- 2.14 days for the noncritical group (mean +/- SEM, p = 0.75). No patient in either group progressed to occlusion in the interval between arteriography and endarterectomy. Perioperative strokes occurred in two patients (2%) in the critical group and four patients (3.6%) in the noncritical group (p = 0.09). Likewise, no significant difference was demonstrated in these variables when comparing patients with critical carotid artery stenosis and APO with those without APO. CONCLUSIONS: The presence of a critical carotid artery stenosis including APO did not impact on the treatment or outcome of patients requiring endarterectomy nor did it imply the need for emergency intervention to prevent thrombosis. Surgical intervention can proceed after evaluation and optimization of comorbid conditions without undue concern for interval thrombosis.

Carotid patch angioplasty: immediate and long-term results.

To determine the benefit of carotid patch angioplasty, a retrospective study of 1000 consecutive carotid endarterectomies was done. Based on the type of carotid endarterectomy closure, patients were divided into four groups: 250 had primary closure, 250 had expanded polytetrafluoroethylene patch, 250 had Dacron patch, and 250 had saphenous vein patch. On the basis of operative technique or type of carotid artery closure, no statistical difference was found in the incidence of postoperative stroke (p greater than 0.25): primary closure 1.6% (4), expanded polytetrafluoroethylene 2.0% (5), Dacron patch 1.6% (4), and saphenous vein patch (0). Postoperative carotid patency was determined by B-mode ultrasonography, and 717 patients were evaluated in follow-up extending to 6 years (mean 37.8 months). Based on the method of carotid endarterectomy closure, no significant difference (p greater than 0.25) was found in the incidence of significant restenosis (greater than 50% diameter reduction): primary closure 4.0% (7), expanded polytetrafluoroethylene 4.0% (6), Dacron 5.4% (9), and saphenous vein 1.0% (2). Significant restenosis was most frequent in habitual smokers (93%, 25/28) and females (78%, 22/28) despite the method of carotid endarterectomy closure. No statistical difference was found in the incidence of late ipsilateral stroke either (p greater than 0.25): primary closure 2.9% (5), expanded polytetrafluoroethylene 2% (3), Dacron 5% (3), and saphenous vein 0%. These results indicate that the incidence of postoperative stroke, regardless of method of arterial closure, was not statistically different. The method of carotid closure did not appear to affect the occurrence of late ipsilateral stroke or restenosis; however, patch angioplasty with saphenous vein appears appropriate in habitual smokers, and likely in patients with small internal carotid arteries.